People who are hearing-impaired, or unable to speak, communicate via the telephone network by using specialized text terminals, commonly referred to as a Telecommunication Device for the Deaf (“TDD”) or a teletypewriter (“TTY”). A TTY converts symbols (letters, numbers, punctuation, etc.) typed on its keyboard into audio signals that it transmits through the telephone network to another TTY. The receiving TTY converts the audio signals back into symbols and displays them on its display screen. A call between TTYs is established and terminated in the same manner as between telephones: either the TTY emulates the call signaling of a telephone, or the TTY user uses a standard telephone to initiate, dial, answer, and terminate the call, and uses the TTY only for the traffic-exchange portion of the call. The TTY usually connects to the same analog RJ-11 line as the telephone via an RJ-11 splitter.
In Voice over Internet Protocol (“VoIP”) networks, softphone applications, such as Avaya IP Softphone™, IP Agent™, and One-X Agent™ manufactured by Avaya, Inc., allow an associated desktop computer to serve as the physical telephony endpoint for voice conversations. By the softphone application, the user can perform normal telephony functions directly through the computer.
These softphone applications have multiple, discrete modes. In a road warrior mode, the user's headset or handset is plugged into the computer's USB port or sound card, and the user engages in VoIP calls using the sound card of the computer. In other words, the computer serves as the physical telephony endpoint for the voice conversation. In a telecommuter or dual connect mode, the user receives toll quality audio via a standard telephone having a separate Public Switch Telephone Network (“PSTN”) connection to the server. In this mode, the associated telephone is controlled by the softphone application. Examples of functions under the control of the softphone application, include dialing, hold, conference, and the like. When the user goes “off hook” with the softphone application, the associated telephone number provided to the softphone application by the user is called, and the user's conversation places on the associated telephone. When answered, the call is supported by the associated telephone and not by the computer's sound card. During the conversation, the user retains control of the softphone application. Another discrete mode includes the shared control mode (in which the associated telephone is controlled by both the associated softphone application and server whereby the user can dial from his or her IP network connected Personal Digital Assistant (“PDA”) through the user's desk phone).
Softphone applications are voice-only and do not have embedded support for non-voice telephony applications, such as TTY, or for special telephony applications, such as video. Embedded support, though possible, can become expensive very quickly because of the large number of different formats and media that would need to be supported. Illustratively, with the European Union alone there are six different incompatible TTY protocols (e.g., European V.18, V.21, EDT, Mintel, and 50 baud Baudot), some of which require the endpoints to respond appropriately to a handshake tone and then maintain a constant carrier tone. A further complication is that the EU protocols are not compatible with the TTY protocols used most commonly in the United States (e.g., 45.45 baud Baudot and TurboCode)
Although it is possible for softphone applications to control the behavior of auxiliary special-purpose (adjunct) telecommunication devices (thereby providing a solution when the embedded voice-only interface is inadequate), the user must switch manually back-and-forth between the various modes to configure the softphone application for one mode or the other before the arrival of a specific type of telephone call. Illustratively, a contact center agent who is configured for “road warrior” mode cannot interact with an unexpected TTY-using customer or multimedia (video) call; similarly, a TTY-equipped agent who is configured for “telecommuter” operation is unable to accommodate voice callers.
A common approach in contact centers is to use server-based functions to identify calls that cannot be accommodated by voice-only soft clients. For example, methods that allow inbound calls to be identified as needing 45.45 baud Baudot TTY support include (a) the caller dialed-in using the contact center's TTY phone number; (b) the caller selected “Standard TTY” in an auto attendant menu; and (c) the gateway detected that the caller was transmitting 45.45 baud Baudot TTY signals. Once detected, these calls are routed to appropriate special-purpose endpoints. Although the server can identify the special requirements of these calls and route them to appropriate devices, the agents who answer the calls do not have access to many of the auxiliary functions provided by contact center agent-facing software.
In another approach, the contact center runs the softphone in telecommuter mode, with a TTY designated as the associated physical device. This poses a problem. A softphone can be in road warrior mode or telecommuter mode, with no automatic ability to switch from one mode to the other based on the media requirements of the call. Moreover, a softphone in telecommuter mode can have only one associated desktop device, with no automatic ability to choose among a variety of desktop devices depending on the media requirements of the call.